350 distributor gear puzzling UGLY wear

Discussion in 'Small Block Tech' started by gsjohnny1, Nov 28, 2021.

  1. 1987Regal

    1987Regal Well-Known Member

    This is the second cam gear on this dist. this is my old distributor I kept for parts the first gear on this distributor was way worse
     

    Attached Files:

  2. Dano

    Dano Platinum Level Contributor

    Great - Now I have "we don't need no oil filter" stuck in my head - Thanks!, lol
    I tend to agree. Seems high volume & lower pressure is the way to go. I suspect the NHRA SS guys aren't running more than 40-50 psi WOT.
    More stuff we should've saved back when parts cars were plentiful.
    Agree John - Unless it's just an alignment issue, my $ is on the high pressure. See what pressures those guys are running too. Seems the front mount exterior pump would be something to consider. Probably takes much less HP to run as well & would result in more consistent timing.

    BTW, is this gear issue what took you out at Cecil?
     
  3. sean Buick 76

    sean Buick 76 Buick Nut

    Mark Burton always used the high volume pump kits and said he had no issues.
     
    Max Damage likes this.
  4. Fox's Den

    Fox's Den 355Xrs

    When you put Mobil 1 in a steel cup and put a torch to it the oil just bubbles and did not burn
    I did the same thing with regular oil and it smoked and turned black
    Can't burn with a torch can't burn in an engine.

    Next year 2022 makes 28 yrs on those gears in previous pics I am the Only one that has done this and for this long

    Hv oil Pump, Oil mods done to engine, Adjustable oil regulator all set up by TA, 10-30 Mobil 1, 25+ years no issues.
     
    Mark Demko and Dano like this.
  5. Mart

    Mart Gold level member

    Don't forget about the 2 qts of 20-50.
    Somehow, those 0-20 & 5-30 weight oils seem water like to me....:D
     
    mikethegoon likes this.
  6. Max Damage

    Max Damage I'm working on it!

    I have also been running this setup (without T/A's help and without the pressure regulator).

    Mine has been running since 1990ish (about 22 years & 40k miles).

    Interestingly I also run Mobil 1.

    The guy who helped me rebuild my engine here in Seattle was a former shop teacher, who had done an experiment with the help of his class and Boeing corporation which donated two identical Chevettes to the class. They broke the cars in according to the manuals, and then ran one on Mobil1 and one on conventional oil. Then the cars were put in use in use with the school system for 2 years and about 30,000 miles (as I recall). Conventional oil changed every 5k Mobil1 every 10k.

    After that the filters were were pulled and sectioned and sent to University of Washington, where the sections were burned in a photospectroscope. Both engines were torn down and compared. Jay Sr. (that's all I can remember of his name) reported that both engines looked ok, but the Mobile 1 engine looked new. Also, the filter from the conventional oil engine had a lot of metal deposit in the filter when compared to the Mobile1.

    Up until that moment I had never considered using this product. After breaking in the 350, I have used nothing else in either of my cars. When I switched over the Mobile one in the 400 I did have to chase some minor leaks, as it's "more watery" as Mart points out.

    I know engine oil is a religious subject, but so far so good here.
     
  7. gsjohnny1

    gsjohnny1 Well-Known Member

    with a couple of unsolvable issues, i going to use a plain used engine for a blower setup for now. (this ought to be fun)
    have to find out where my coolant issue is.
    discussed with my son and maybe think that the t/c is no good. maybe oem t/c's are no good for a blower app.
    anybody have the new a/mrkt t/c? did you compare it to the oem?
    fishing season ought to be good with this can of worms....:eek::D
     
  8. Fox's Den

    Fox's Den 355Xrs

    is it the timing cover or is it the blower pushing so hard the gear on the end of dist can't keep up with the pressure and quick rpm the thing is bending outward trying to keep up.
     
  9. JESUPERCAT

    JESUPERCAT No Slow Boat

    John the coolant issue is, if you didn't put it in it won't keep leaking out:D alcohol is your friend. Not just relaxing either...
    The blower is not putting much pressure on anything other than the crank snout. It doesn't load the gears like thick oil or bad clearance issues would.
    What does the pump assembly look like internally? Also how much vertical movement is in your distributor shaft.
     
    Max Damage likes this.
  10. Mark Demko

    Mark Demko Well-Known Member

    Only difference between an OEM cover and aftermarket I've noticed is the way the crank seal installs.
    Is there a reason you think the OEM cover wouldn't work with a blower?
    Whats wrong with your existing cover?
     
  11. Mark Demko

    Mark Demko Well-Known Member

    Off topic here but thought I'd put this in here,
    All the talk about "running iron gears in an aluminum housing" in regards to the Buick oil pump, most all, if not all engines today do the same thing, and the pump is front mounted.
    I see this more and more, a lot of similarities between new engine design and Buick's 350
    Was Buick that far ahead of the curve in engine design WAAAAY back then???
     
  12. mikethegoon

    mikethegoon Well-Known Member

    What would happen if my cam thrust had showed uneven wear. It was a pattern that as it rotated started as a thin line then showed a full swipe. I.e. full contact of thrust surface.. The cam original stamping ID had been obliterated by someone with a series of stampings . I believed was a Schneider old stock .. I have since moved on to comp cams. But I have seen my buddy put a cam on crank jig to straighten it.
     
  13. Fox's Den

    Fox's Den 355Xrs

    I understand that my thinking is as the blower is building up more pressure as rpm is building is that pushing too much at 7500 rpm and the timing chain along with the gears can't keep up. Does this make any sense? I don't know just trying to think out of the box I am just thinking physics here rpm x oil driven gears off the dist all sandwiched together, driven real hard by a blower to 7500 rpm.
     
  14. gsjohnny1

    gsjohnny1 Well-Known Member

    if i went to alcohol......:D. damn, wrong alcohol. thought about it numerous times, but just try it once. don't want the driver addicted. lol
    the water leak is puzzling and see no cracks or rust spots. only item left is the t/c.
     
  15. Max Damage

    Max Damage I'm working on it!

    I don't see how the blower would have any effect?
     
    72gs4spd likes this.
  16. gsjohnny1

    gsjohnny1 Well-Known Member

    the t/c is certainly not the hardy's piece of metal on it. w/p, alt pullies have an effect. the dizzie moves with the camshaft/gears up's/down of rpm's.
    and then there is the mystery of why all this is happening. nobody ever tested these engines for what we do them.
     
  17. Fox's Den

    Fox's Den 355Xrs

    The blower pushes the engine a lot harder than NA doesn't it? Nitrous does the same thing it pounds that piston to the bottom of the engine. The blower starts to push harder as the rpm goes up. The blower pushes the piston, which drives the timing chain which then turns that gearing at the dist and cam.

    All those parts have to keep up with the blower ramming the piston to the ground and as rpm goes up it pushes harder. That is my thinking it might be wrong it may not matter but I don't see anybody else coming up with an answer. I am just trying to think out of the box.

    Maybe this does not happen until the engine starts to push past 7 grand I am just trying to think physics on this.

    If the dist and the gearing can't keep up with the fast rising rpm and the oil is slowing down the the whole thing something has to bend and maybe the gear and the dist is pushing out because it can't keep up with the rapidly climbing rpm.

    does this make any sense?

    in the end it is probably a bad timing cover.
     
  18. Mart

    Mart Gold level member

    That would be worth checking out.
     
  19. Jim Blackwood

    Jim Blackwood Well-Known Member

    It's a purely mechanical system. The shaft shouldn't flex enough to get more wear on one side. Let's be clear about what is going on here. What I'm hearing is that as the distributor gear spins, there is excess wear on one side and 180 degrees of rotation away it looks more normal, is that right? The ONLY thing this gear drives is the oil pump. The distributor shaft just goes along for the ride. The length of the oil pump gears cannot affect this because the oil pump is on a slotted drive. Unless the oil pump shaft is bent somehow and even then only if it is bent in line with the flats of the drive so that it could push the distributor shaft sideways.

    What could cause it is if the distributor shaft is bent or the gear is somehow cocked. But the alignment of the housing won't do it. Because it is a 1:1 drive, the driving gear on the cam could also do it, if it was out of line somehow, either off center or cocked but none of this has anything to do with it being a roller cam.

    I'd start by indicating the snout of the cam and make sure that's running true and has no play, and then do the same thing for the distributor shaft installed in the cover. Then check the gears with the indicator to make sure the tips of the teeth are concentric with the shafts and check them at the sides to make sure they are square with the shaft they run on. You should find your problem there somewhere. It might be possible the cam is shifting fore and aft once per revolution so check for that too. Seems doubtful the dizzy shaft would be moving up and down but that's another check. Somewhere there you should find the answer, that's where it has to be. You might also check the hole for the oil pump shaft to be sure it is concentric with the hole for the distributor and perfectly parallel with it. It is just conceivable that a bad misalignment out of parallel or concentricity could do it.

    Jim
     
    Darron72Skylark likes this.
  20. gsjohnny1

    gsjohnny1 Well-Known Member

    jim,
    preface that gear out has been constant since racing the 350, aka high rpm. but not like now.
    i changed t/c because the the dizzy was sloppy in the hole. i.e. the t/c hole was stretched. that set of gears are just like this set. have 4 teeth od's are are worn down, like the setup was bouncing around. this set of gears was heat treated, polished and coated.
    beginning to wonder if the 350 t/c can't handle rpm abuse.
     

Share This Page